"A thorough investigation was carried out and the man has now been issued with a formal warning," a spokeswoman said. "We encourage families and community members that if they have concerns ... to report it to police confident in the knowledge that their complaint will be investigated." Laws yesterday denied receiving a formal warning from the police.
"That is false ... you're lying to me because I know they are bound by the law not to discuss that, and I haven't received any formal warning at all."
The controversial anti-smacking law, championed by former Green MP Sue Bradford, came into effect in 2007, and removed the defence of reasonable force for parents prosecuted for assault on their children.
Bradford said on Friday police were administering the law well, including the use of warnings.
"I don't know any details but it sounds like the police have acted in the usual way ... I hope that [Laws] takes what's happened seriously. It sets a very poor example from someone who has held public office."
A 2009 referendum found an overwhelming number of people did not believe a smack as part of good parental correction should be a criminal offence.
Last year, Laws wrote in a newspaper column that he believed in smacking.
"I can report both its effectiveness and the fact that neither the police nor CYF have visited. They won't either, because the law may be an ass, but its application is not."
Laws was a Whanganui District Health Board member at the time of the alleged incident, and was elected to a third term in October before resigning and moving to Timaru for a new job as development manager at state-integrated girls' school, Craighead Diocesan.
Board chief executive Julie Patterson declined to comment on the police decision.
"We would suggest that an incident such as you describe is clearly a police matter."
Health board chairwoman Dot McKinnon said she was appointed after the incident and would only say the nurse's complaint was "a routine response".